MUSEUM OF COMPAKATTVE ZOOLOGY. 229 



a high spine-ridge, meeting above and below. Upper arm-plates small, broader 

 than long, fan-shaped, with an angle inward. Disk round and high, covei-ed 

 above and below with very minute stumps, which often are forked, and which 

 conceal the scaling of the disk. Radial shields long and narrow, concealed by 

 the disk-stumps, except their outer tips. Genital openings large, extending to 

 margin of disk. Nine or ten long, slender, thorny, translucent arm-spines, 

 whereof the highest and largest nearly meet on the upper surface of arm, and 

 are as long as three or four arm-joints. One large flat tentacle-scale, bearing long 

 thorns, which give it a palmated look. Color in alcohol, straw. 

 Sigsbee, off Havana, 175 fathoms, 6 specimens. 



Ophiacantha scutata sp. nov. 



Plate I. Figs. 1-3. 



Special Marks. — Disk above evenly set with small cylindrical stumps 

 having thorny ends. Long, narrow, separated radial shields. Nine slender, 

 slightly thorny arm-spines. Seven pointed, widely spaced mouth-papillae. 



Description of an Individual. — Diameter of disk 10 mm. Width of arm 

 without spines 2.3 mno. Seven long, rounded, tapering, pointed mouth-papillaj 

 to each angle, the one at the apex being largest. Mouth-shield broader than 

 long, with a wide angle within, and a curve without. Side mouth-shields wide 

 without and narrow within, where they nearly or quite meet. Under arm- 

 plates shield-shaped, outer side strongly curved and much wider than the 

 inner, which makes an obtuse angle ; laterals re-enteringly curved ; the first 

 plate is unusually large. Side arm-pktes large and swollen, meeting narrowly 

 above and below. Upper arm-plates triangular, much swollen, having a 

 rounded edge without and an obtuse angle inward ; when dry, they show two 

 longitudinal cracks. Disk round and high, covered with minute cylindrical 

 stumps with thorny ends. Radial shields long, narrow, of nearly equal width, 

 with straight sides, and widely separated. Lower interbrachial space covered 

 with thin, smooth, rounded, overkpping scales, carrj-ing few or no stumps. 

 Genital openings large and long, having a small, narrow scale, which is wider 

 without than within. Eight or nine stout, thorny arm-spines, the three upper 

 ones longest, and about as long as four arm-joints. One long, stout, pointed 

 tentacle-scale on the inner edge of tentacle-pore ; the first pore has two. Color 

 in alcohol, pale straw, but bright brick-red when living. 



Station 16, 292 fathoms, 1 specimen. Station 21, 287 fathoms, 1 specimen. 



Ophiacantha echinulata sp. nor. 



Plate I. Figs. 7-9. 



Special Maries. — Disk closely set with fine spines. Beyond the first pore, 

 one long, sharp, dagger-shaped tentacle-scale. Nine long, very slender, glassy, 

 thorny arm-spines. 



Description of an Individual (Station 29). Diameter of disk G mm. Length 

 of arm 40 mm. Width of arm close to disk, without spines, 1.5 mm. Eleven 



